简并征期是指实行（）交纳税款的纳税人，经税务机关批准，可以采取将纳税期限合并为按季、半年、年的方式交纳税款。

A.查定征收

B.定期定额

C.委托代征

D.代收代缴

——Do you have any idea when the project will be carried out?

—No, but I have heard that it was not until last month _______ it was approved.

A．that

B．when

C．since

D．before